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Clogged arteries are very dangerous

Conway McLean, DPM

Everyone knows at least something about the importance of blood flow, and perhaps a bit about some of the problems. “Hardening of the arteries” they call it, which sounds rather uncomfortable but not all that serious. What many people don’t know about this topic, reduced blood flow to the extremities, can hurt them. This is generally referred to as peripheral arterial disease, or simply PAD.

The statistics regarding PAD are significant and startling. The incidence of this clogged artery problem has been estimated to be as high as 20% of the general population. The peripheral part refers to the extremities, the arms and legs, but the complications primarily occur in the latter. If this number is even close to the truth, why don’t more people complain of the pain and problems associated with PAD? The reason is many have it but have no symptoms…..yet.

But the subject of this article is actually not PAD, it is Critical Limb Ischemia, the condition which develops when your arteries become severely clogged. This clogging process involves the deposition of atherosclerotic plaque inside arteries. As more of this material builds up, as the PAD increases in severity, at some point it becomes ‘Critical Limb Ischemia’ and, as the name implies, this can be a serious situation.

Although it is an extension of PAD, Critical Limb Ischemia (called CLI) carries with it some very dangerous repercussions. Those with critical limb ischemia have a higher rate of heart disease, since blood vessels throughout the body will be affected by this process. For this reason, CLI is strongly associated with cardiovascular risk factors such as cigarette smoking, diabetes, high cholesterol levels, and hypertension. CLI represents the most aggressive form of peripheral vascular disease, with a lower survival rate than heart failure, stroke and most cancers.

The term ‘ischemia’ is an important one, referring to the condition of being deprived of blood. The dangers are real: blood is necessary to all living tissues. Any part of the human body that is alive will sicken, then die, if deprived of blood. Everyone is familiar with dead tissue: it’s called gangrene. But there are many pathologic changes prior to that.

Estimates claim about ten million Americans suffer from this disease, whereby arteries become clogged. The number of people diagnosed grows every year. It works out to about 12 out of every 100 adults suffer from critical limb ischemia (although this doesn’t refer to how many have been diagnosed). There is a higher incidence in men vs women, and is also more common in the elderly. About one out of five adults over the age of 70 carry a diagnosis of critical limb ischemia.

The clinical presentation experienced by those with PAD are varied and many. There may be no symptoms or perhaps pain with certain levels of activity, labeled to intermittent claudication. When the condition progresses to the point of becoming CLI, there will be additional changes. They may not be obvious to a casual observer, but to a physician specializing in this region of the body, the changes are obvious.

Certain signs of PAD are associated with certain levels of the disease. When the plaque build-up reduces blood flow sufficiently, pain may be experienced in the feet and lower legs when the afflicted individual lies flat. This pain is due to the tissues in the lower extremity being deprived of blood, since gravity is not helping pull the blood down. It’s termed “Rest pain”, with the pain relieved typically by standing. These individuals are generally very limited in what they can do physically.

The structures affected by CLI are those parts of the body most deprived of blood. These are the structures farthest from the heart, where the greatest amount of vessel-clogging disease will have occurred. Thus, these changes are first seen in the toes and feet where the skin becomes dry and thin, the toes cold, the nails thickened and discolored. Others symptoms may include leg pain, rest pain or cramping.

As with many things in nature, this is not ‘black and white’ issue. PAD is not an infection, where one day you are fine, then the next you have a flu. The changes are gradual; the development of CLI occurs over time, with the effects easy to miss. With a health care system more attuned to health maintenance, the development of ischemic disease might be recognized and the course of the disease altered. Unfortunately, this is rare and, generally, no intervention is instituted prior to the occurrence of obvious pathology, such as a wound that won’t heal.

Many of these types of ulcers occur in the toes and feet, the areas receiving the least blood. This also happens to be the structures enduring the most physical insult in the course of a normal day, supporting us, moving us from place to place, all while crammed inside a shoe. An ingrown nail, a thickened callus, shoe gear fitting improperly, many kinds of minor injuries lead to amputation due to the presence of CLI. Tissue repair is impossible without a sufficient supply of this life-giving substance.

Diabetes is a major risk factor for all forms of cardiovascular disease. Diabetes greatly increases the risk of CLI, as well as accelerating the course of the disease, making these patients more susceptible to ischemic events, such as a non-healing wound, or the ‘throwing’ of a blood clot.

When the signs or symptoms have progressed, when pain develops or there is a skin injury that won’t heal, intervention becomes necessary. The best results are obtained when a multidisciplinary approach is utilized, which reliably improves the outcomes in these patients. Intervening in this process of critical limb ischemia can have a significant social and economic impact. A major amputation has profound consequences on health and well-being, along with the associated financial burden on our health care system. Studies reveal the cost of managing a patient after amputation is nearly twice that of successfully saving a limb with the use of minimally invasive surgical techniques.

But when the condition is recognized prior to the development of serious consequences, conservative measures, primarily lifestyle changes, can sometimes be effective. These are difficult to make and maintain, a requirement for benefits to be seen from healthy efforts like exercise. Research has clearly demonstrated we can grow new blood vessels through appropriate physical activity. Certain forms of electrical stimulation therapy are used to improve blood flow and thus aid in healing of an ischemic wound.

Minimally invasive blood vessel surgeries, referred to as endovascular procedures, are those performed from inside the blood vessel. The goal is to enlarge the opening of the artery, allowing more blood to get down to the deprived tissues. These endovascular techniques, usually of one of two types, either angioplasty or atherectomy, are now used more often than bypass surgery as the initial therapy. A new technology entails the use of shockwave technology when performing balloon angioplasty, a novel way to disrupt calcified plaque.

Chronic limb ischemia reflects the local manifestations of a lethal systemic disease: atherosclerosis. If you have a cut or scrape on your foot that is not healing properly, you may have CLI. A referral to a vascular specialist may be the key component of care leading to closure. A wound care specialist will recognize the reason the injury is not healing and arrange for a consultation in the hope the vessels can be opened up and adequate flow restored. With sufficient vascularity, healing can occur. Yet, early recognition is a healthier approach. Dare I say it? “An ounce of prevention is worth a pound of cure.”

Editor’s note: Dr. Conway McLean is a physician practicing foot and ankle medicine in the Upper Peninsula, with a move of his Marquette office to the downtown area. McLean has lectured internationally on wound care and surgery, being double board certified in surgery, and also in wound care. He has a sub-specialty in foot-ankle orthotics. Dr. McLean welcomes questions or comments atdrcmclean@outlook.com.